1. Technical Field
The present invention relates to an image forming apparatus that backs up and restores job data saved in an internal storage unit into another storage unit, and to a job data management method.
2. Description of Related Art
Image forming apparatuses using an electrophotographic system or the like for use in offices have been applied even to the print on demand (POD) market along with their higher-speed performance and higher functionality. Recent years have seen an expansion of uses of such image forming apparatuses.
In general, a printing-out process is as follows: a print job, which contains image data and a job ticket in which print settings are described therein, described in a printer language (PDL: page description language) is input to an image forming apparatus from a personal computer (PC). Then, the input image data is subjected to rasterization processing by a raster image processor (RIP) to generate raster image data, and based on the generated raster image data, an image forming unit forms an image on paper.
In image forming apparatuses applied to the POD market, print settings made by user are becoming more complicated in response to higher functionality and higher image quality. Then, in many cases, a work flow is employed in which tuning of print settings is done while confirming output results of a print job by test printing, and then final printing is performed.
Most image forming apparatuses for POD jobs are provided with a job saving and editing function for supporting such a work flow. The job saving and editing function saves, as a “saved job”, a print job input to an image forming apparatus in a storage region inside the image forming apparatus to allow subsequent changes in print settings. Even when print settings are changed after input of a print job from a PC, the function allows the saved job to apply the changed print settings so that printing is performed using the post-change print settings. This makes it unnecessary to input the print job again from the PC.
In addition, Japanese Patent Application Laid-Open No. 2013-106126 (Patent Literature 1) discloses a technique in which a print job and a raster image obtained by rasterization of the print job are saved together and reused. The technique allows omission of rasterization in printing so that further productivity improvement can be achieved. Patent Literature 1 also discloses a technique for backing up a saved job, in which, when both image data and a raster image are saved, only the image data will be backed up, whereas when either one of the data is saved, the data will be backed up, together with a technique for restoring the backup data for reuse.